Waterfox browser
The problem with Waterfox is that it is run entirely by one guy, who pulls Firefox updates as and when he has the time to. You might end up waiting several days or even weeks for critical Firefox updates to find their way to Waterfox, so it does become a bit of a security risk. All the changes that Waterfox makes vis-ŕ-vis privacy can also be applied to Firefox with a little bit of tweaking and some add ons. Here's the link to a post I made a couple of months ago with the relevant Firefox tweaks to improve privacy: https://bitcointalk.org/index.php?topic=5134800.msg50754832#msg50754832.Another great resource for setting up Firefox is here: https://www.privacytools.io/browsers/
Support for legacy extensions is also available through Firefox ESR, so that's not a good reason for using Waterfox either.
I agree regarding Waterfox, BUT you can not fully remove Telemetry from Firefox.
Last version Waterfox 56.2.12 Released July 10, 2019
It is not my 1st choice browser, but I can use it as alternative.
One more good website is:
https://prism-break.org/en/all/#web-browsers